HISTORICAL SKETCH 35 



1813, Keating.] 



the nature of the rock, which breaks into angular, and apparently rhomboidal fragments of a huge 

 size, this fall is subdivided into several cascades, which adhere to each other, so as to form a sheet 

 of water, unrent, but composed of an alternation of retiring and salient angles, and presenting a 

 great variety of shapes and shades ; each of these forms in itself a perfect cascade; but when taken 

 together in one comprehensive view, they assume a beauty of which we could have scarcely deemed 

 them susceptible. We have seen many falls, but few which present a wilder and more picturesque 

 aspect than those of St. Anthony.* 



Prof. Keating gives the following section of the bluff at Fort Snelling, 

 in descending order: 



1. Limestone, of a distinct slaty structure ; compact, but with a splintery uneven fracture ; 

 filled with organic remains (Producti) ; of a light grayish-yellow color ; 8 ft. 



2. Limestone, of a blue color, destitute of fossils ; an excellent stone for building, and good 

 for quicklime. 1520 ft. 



3. Sandstone, constituting the principal mass of the bluff. This is friable, but every frag- 

 ment, examined with care, seems to be a regular crystal. Keating inclines to the opinion that it 

 must have been from a chemical precipitation, and not from mere mechanical deposition. The proc- 

 ess of its formation may have been a very rapid one, such as is obtained in the manufacture of 

 fine salt ; and to this may be attributed the circumstance of its fine texture. The color is white 

 sometimes a little grayish, when it resembles the finer varieties of Muscovado sugar. 60 ft. 



4. Limestone ; slaty, striped with curved zones ; very argillaceous, softer than the preced- 

 ing ; structure quite earthy ; color light yellow. 10 ft. 



5. Limestone ; bluish, or yellowish gray, conglomeritic with small black pebbles of quartz ; 

 more crystalline than the last ; vesicular ; rises four feet above the level of the river. 7 ft. 



6. Limestone ; much finer grained and more earthy than the last. The bed of the river near 

 the fort is excavated in this limestone.! 4 ft. 



He remarks that at the falls of St. Anthony the same section may be 

 een, except that the lower limestones are not there visible. The foregoing 

 limestones, stated to lie below the sandstone at Fort Snelling, must have 

 been large fallen fragments from the top of the bluff, since no subsequent 

 observer has ever reported them. Mr. Featherstonhaugh makes the same 

 correction. 



KEATING ON THE MINNESOTA EIVEE. 



At the Indian village of Taoapa, estimated at thirty-seven and one-half 

 miles from Fort Snelling, probably the same place as Shakopee, Major Long 

 observed limestone which appeared to him to be in situ. 



Keating mentions the rapids at Carver, "caused by two bars of sandstone," 

 the first forming a fall of four feet in twenty yards. Half a mile above this 

 is a second bar. The aggregate fall is estimated to be seven feet. This 

 sandstone is seen in the bank, and "resembles that at Fort Snelling. It 



Major Long's party forded the river above the falls, walking on the rock from the west to the east side Prof 

 Keating, who was debilitated by a fever, succeeded in reaching only the island dividing the fall, and with great difficulty 

 returned to the west bank. 



tOompare Bulletins of the Minnesota Academy of Natural Sciences, Vol. 1, p. 91. 



